The present invention relates to snow plows which mount on a motor vehicle, and more particularly to snow plows which are removably mounted on the rear of a motor vehicle and are carried off the ground when not in use.
The prior art is replete with motor vehicle mounted snow plows, some are even mounted on the rear of a motor vehicle. The generally accepted snow plow arrangement for use on highways and the like is the pusher type which mounts on the front of a vehicle. This type of snow plow can be set to push the snow off to the side of the highway and continue to move, thereby covering a large area in a short time. The problem with pusher type snow plows is that they are not effective in confined areas, such as driveways, where there is no room to get behind the snow. Front end mounted snow plows are usually backed up to a garage or end of a driveway which leaves an area the length of the vehicle unplowed.
Rear mounted snow plows which are pulled through the snow are suited for removing now close to a wall, garage or around a driveway. They are not well suited for highway snow removal. In general, rear mounted snow plows have a blade and side plates to scrape snow and trap it between the blade and the side plates.
The currently used snow plows are raised and lowered by a hydraulic or electric system which operates mechanical linkage between the plow and the motor vehicle. Older snow plow systems were strictly mechanical. Often raising and lowering mechanism is complex, requiring several lever arms and hydraulic cylinders. It would obviously be desirable to accomplish snow removal without the need for complex equipment.
The inventor is aware of several U.S. Patents on the subject of towed snow plows. There are patents which are directed to snow plows secured to the rear of a motor vehicle and which are attached by pins to the rear of a vehicle, these are U.S. Pat. Nos. 1,161,275, 3,483,641 and 4,506,465. These types of constructions differ from my construction where my rear plow is secured by a draw type hitch and is mounted with draw arms to ears fastened to the hitch. The advantage is that when the plow apparatus is removed the tow vehicle only has the basic hitch left on it permitting the tow vehicle and its hitch to be used to tow other apparatuses such as a horse trailer or a boat trailer and the like. This arrangement herein disclosed is very clear for by removing three pins the plow apparatus is removed in a few moments of time. Two front mounted snow plows are disclosed in U.S. Pat. Nos. 3,640,005 and 3,483,641. Of the above patents, only U.S. Pat. No. 3,640,005 discloses a linkage for raising or lowering a snow plow blade which is of interest regarding the present invention.
The present invention has a relatively simple method to raise and lower a rear mounted snow plow, as will be hereinafter described.